Named after the Norse goddess of youth, the Seas Idunn kit sets a high standard for DIY speakers. Cabinets come fully assembled in black ash, cherry, or maple, and the crossover also comes prebuilt, so installing it is just a matter of affixing it to the boxes and attaching the drivers. All told, the build took me about two hours using basic hand tools. To get speakers that look and sound this good, you’d normally pay several thousand dollars.